Vibrating element flow measurement apparatus

Abstract

The invention describes a vibrating element apparatus, preferably in the form of a tuning fork-type contact level transducer, and a method of forming the same. The tines of the transducer are vibrated by piezoelectric elements, which piezoelectric elements are arranged in a stack along with insulators and conductors to allow cyclic electrical signals to be applied thereto. The stack is provided as a sub-assembly allowing ready replacement in the field and 10 without disturbing the installation of the transducer in the plant which it serves.

The invention claimed is: 
     
       1. A vibrating element apparatus including:
 a wall section having an inner surface and an outer surface; 
 a diaphragm defining, and closing one end of, said wall section, said diaphragm having an inner surface and an outer surface, the inner surfaces of said wall section and said diaphragm defining a hollow body; 
 one or more vibrating elements extending from the outer surface of said diaphragm; 
 a stack comprised of components which include one or more piezoelectric elements, said stack being located within said hollow body; and 
 a compression device operable to compress said stack against the inner surface of said diaphragm; 
 wherein said apparatus further includes a carrier which houses said stack and said compression device, said carrier being configured to fix the position of said stack with respect to said hollow body yet allow said compression device to rotate with respect to said stack ( 22 ), said carrier, said stack and said compression device being engageable with, and dis-engagement from said hollow body as a sub-assembly. 
 
     
     
       2. Apparatus as claimed in  claim 1  wherein said carrier further houses at least one thermal compensation element. 
     
     
       3. Apparatus as claimed in  claim 2  wherein said carrier includes a channel to house wires in electrical contact with said piezoelectric elements.